Hindu priests from Varanasi were called to offer prayers at the function, said Acharya Kishore Kunal, secretary of Mahavir Mandir Trust that is building the temple complex.

The complex would come up in about 100 acres at a cost of Rs.600 crore, he added.

Kishore Kunal said the temple's construction plan has been revised and it would be bigger than the 12th century temple in Cambodia, considered by some as the largest Hindu temple complex in the world.

Angkor Wat was built during Hindu king Suryavarman's rule and is today a Unesco World Heritage site.

The proposed 'Virat Angkor Wat Ram Mandir' in Bihar will have idols of Radha-Krishna, Shiva-Parvati, Ganesh, Surya, Vishnu and Dashavataram - the 10 incarnations of Vishnu, Kishore Kunal said.

It will be designed by a temple architect from Ahmedabad, Piyush Sompura.

The five-storey -- 270 feet tall, 2,800 feet long and 1,500 feet wide -- structure will be one of the tallest temples in the world, said Sompura, who will also raise funds for the project from India and abroad.

"We have already collected Rs.200 crore and the remaining amount is expected to come as donations from people," he said.